Grinding-tool



J. F. MAcDONALD.

GRINDING TOOL.

APPLICATION FILED OCT. 12. 1920.

Patented Oct. 4, 1921.

2 sHEETS-sHI-LET n.

A'TTORN EY J. F. MACDONALD.

GRINDING TOOL.

APPLICATION FILED 0cT.12. 1920.

1 ,392,426 Patented Oct. 4, 1921.

2 SHEETSSHEET 2- H 2% I A 5.9 I 5W 5.9 57 2.9 3a 170 42 Z; Jb/wF/ 1a ,0maz6z M BY M ATTORN EY UNITED TATES JOHN FRANK MACDONALD, OI CHESTER, PENNSYLVANIA.

GRINDING-TOOL.

Specification of Letters Patent.

Patented Oct. 4, 1921.

Application filed October 12, 1920. Serial 110. 416,479.

To all'whom it may concern:

Be it known that I, Join: FRANK MAC- DONALD, a citizen of the United States, residin at Chester, in the county of Delaware and gtate of Pennsylvania, have invented new and useful Improvements in Grindin Tools, of which the following is a speci cation. I

This invention relates to grinding tools and has for its object the provision of a tool designed for rinding or boring out eng ne cylinders Whi e the engine is still in position on the chasses, the idea bein to true up the bore of the cylinder for fitting new or oversized pistons therein.

An important objegt is the provision of a device of this character including a plurality .of grinding shoes andv provided with means whereby these shoes may be expanded or moved outwardly to vary the diameter of the hole bored or ground out so that the device may be used in cylinders of different sizes.

An additional object is the provision of a device of this character which will be comparati'vely simple and inexpensive, highly eflicient in use, durable in service, and a general improvement in the art.-

With the above and other'objectsand advantages in view,'the invention consists in the details of construction to be hereinafter more fully described and claimed and illustrated in the accompanying drawings in which Fi showing the complete apparatus,

Fig. 2 is an enlarged side elevation of the grinder head alone,

Fig. 3 isa cross sectional view on the line 3'-3 of Fig. 1,

Fig. 4 is a longitudinal sectional view through the grinder head,

.Fig. 5 is a cross sectional view therethrough on the line 5-5 of Fig. 4,

Fig. 6 is a detail view of one of theadjusting washers, and v Fig. 7 is a detail and BlGVSttIOIlr of the "bod. L

Rzferring more particularly to the drawthe engine, the cylinders of which are to be bored out and this frame includes an n right ortion 11 provided at its lower .en with eet Y12 and further includes a horizontal pper portion 13. Journaled-through this gure 1 is a side. elevation of my device ings, the numeral 10 designates a supporting frame which is adapted tobe engagedupon support is a vertical shaft 14 upon which is splined a bevel gear '15 meshing with a bevel gear 16 on a horizontal shaft 17 adapted to collar 21. This yoke is formed with rack teeth 22 engaged by a pinion 23 journaled on an extension 24 at the free end of the horizontal arm 13. The shaft 14 is rotated by rotating-the shaft 17 and is fed downwardly by turning the pinion 23 by means of a suitable handle 25. The above described mechanism is the machine with which is associated my novel grinding device.

My grinding device comprises a body 26 which is of the shape of a Maltese cross in cross section and includes a plurality of radial arms 27. This body is formed centrally with a hole 28 revolubly engaged upon the lower end of a shaft 29. Disposed upon theshaft 29 above this body 26 is a circular disk- 30 keyed upon the shaft and provided with a hole 31 within which is engaged a pin 32 carried by a collar 33 on the shaft 29. The upper end of this shaft 29 is threaded for engagement within a threaded socket in the lower end of the shaft 14. Disposed upon the shaft 29 below the body 26 and keyed in place is a disk 34 exactly corresponding to the disk 30. These parts are held in place by a nut 35 threaded onto the lower end of the shaft.29. The confronting faces of the disks 30 and 34 are formed with spiral grooves 36 for a purpose to be described. 1

Associated with each arm 27 of the body 26 is a segment shaped shoe 37 which has its curved side open for holding a grinding -member 38 which likewise has an arcuate face projecting beyond the shoe and which is held in place by suitable screws or the like 39. This grinding member might be formed of. emery, carborundum, or. other suitable abrasive of a nature which will cut or grind away steel or iron. Formed upon the upper and lower ends of the segments 37 are ribs 40 engaged within'the s iral ooves 36 on the disks so that when t edis s are rotated the grooves therein engaging these ribs will cau se the grindi i members to be protracted or 'retracted', as .t e case may be. The body 26 has its arms :27 formed at intervals with sockets 41 within which are engaged coil springs 42 abutting against the inner faces of the segments for normally forcing them outwardly and preventing any looseness.

In the operation of the device it will be seen that the support 10 with the mechanism carried thereby is placed upon the engine with the shaft 14: arranged co-axially with the cylinder to be bored out or ground. The grinding device formed by the members 26 to 41 inclusive, is then brought into play and the shaft 29 thereof is threadedly connected with the shaft 14. The body 26 is then rotated with respect to the disks 30 and 34 to expand or retract the grinding members so that the diameter of the tool will be of the desired size. The pinion 23 is then operated to move the shaft 14 downwardly to bring the grinding member into the cylinder to be bored, after which the shaft 17 is rotated to rotate the grinder. The grinder will of course grind away the cylinder walls and dress them smooth and to the proper diameter. 'The grinding member is of course fed downwardly as required by means of the pinion 23 until the whole cylinder has been treated as desired.

While I have shown and described the preferred embodiment of my invention, it isof course to be understood that I reserve the right to make such changes. in the form,

. construction, and arrangement of parts as will not depart from the spirit'of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A boring tool comprising a shaft, a

jecting from the ends of the shoes and en- I gaged Within said spiral grooves.

2. A boring tool comprising shaft, a body revoluble upon said shaft and cruciform in cross section whereby to have a plurality of radial arms, said arms being each formed with a plurality of sockets, segment shaped shoes slidably associated with .said arms and having sockets within whichsaid springs have their outer ends engaged, grinding members carried by said shoes, ribs projecting outwardly from the ends of said shoes, and disks carried by said shaft and formed on their confronting faces with spiral grooves engaging said ribs.

In testimony whereof I aflix my signature.

JOHN FRANK MACDo ALD. 

